1. Field
Embodiments of the present invention relate to a scan driver and a driving method thereof.
2. Description of the Related Art
A display device, such as a liquid crystal display (LCD) or an organic light emitting diode (OLED) display, generally includes a display panel having a plurality of pixels, a plurality of signal lines, and a driving unit, which drives the display panel. Each pixel may include a switching element, which is coupled to a signal line, a pixel electrode coupled thereto, and an opposed electrode. The pixel electrode is coupled to the switching element such as a thin film transistor (TFT) and the like, and receives a data voltage. The opposed electrode may be formed on an entire surface of the display panel, and a common voltage Vcom may be applied to the opposed electrode. The pixel electrode and the opposed electrode may be arranged on the same substrate or different substrates.
The display device receives an input image signal from an external graphics controller. The input image signal carries luminance information of each pixel, and each luminance has a number or value (e.g., a predetermined number or value). A data voltage corresponding to desired luminance information is applied to each pixel as a pixel voltage, depending on a difference from a common voltage, which is applied to the common electrode, and the pixel displays a luminance, which is indicated by a gray level of an image signal.
A driving unit includes a scan driver, which supplies a scan signal to a display panel, a data driver, which supplies a data signal to the display panel, and a signal controller, which controls the data driver, and the scan driver. The scan driver includes a shift register including a plurality of stages subordinately coupled to each other. The scan driver receives a plurality of driving voltages and a plurality of scan control signals to generate a scan signal. The plurality of driving voltages may include a gate-on voltage capable of turning on a switching element and a gate-off voltage capable of turning off the switching element. The plurality of scan control signals may include a scan start signal (SSP) for instructing start of scanning, a clock signal for controlling timing for outputting a gate-on pulse, and the like.
In the related art, driving circuits such as the scan driver and the data driver are mounted on a printed circuit board (PCB) as a chip to be coupled to the display panel, or a chip of the driving unit is directly mounted on the display panel. However, in recent years, because a scan driver does not require high mobility of a thin film transistor channel, a structure in which a scan driver is integrated into the display panel has been developed instead of forming a scan driver as a separate chip.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.